Key for a plunger type lock



S. M. MOBERG KEY FOR A PLUNGER TYPE LOCK May 8, 1962 5 Sheets-Sheet 1Filed June 1, 1960 TELEI.E.

INVENTOR. 5/6u/e0 M Ma 55/86 AUTO/605V y 8, 1962 s. M. MOBERG 3,033,016-

KEY FOR A PLUNGER TYPE LOCK Filed June 1, 1960 5 Sheets-Sheet 3 Ticill l56a 1 l INVENTOR.

I fi/ama M MGBEEG 444 BY 44 K4 M /3 Arme/vfy States This inventionrelates to a plunger-type of lock having an enlarged head integral withor fixed on one end of a shank or plunger and a separate, enlarged headwhich may be applied to the other end of the plunger and re movedtherefrom by means of a key; and relates, also, to a key suitable foropening such a look. I

Such a plunger type of lock is commonly used to hold, in lockedrelationship, two members having similar apertures which may be movedinto such relationship that the two apertures are in alignment. Theplunger of the lock, minus the mentioned removable head, may be insertedinto and through said apertures, whereaiter the removable head may beapplied endwisely to the plunger and be removable thereafter only by theuse of a suitable key. The two heads, of course, are of greater diameterthan the two apertures, so that once the lock is in place in associationwith the two mentioned apertured members, the latter cannot bematerially moved or separated except upon unlocking of the lock with thekey and removal of the lock from the apertured members.

Such locks and keys therefor are not fundamentally new; however, thepresent invention has, for an important object, the provision, for sucha lock, of an improved key which is not easily duplicated, and which maybe easily manipulated to open the lock.

Another object of the invention is the provision of an improvedplunger-type lock which cannot be opened by prior keys designed for usewith prior locks, and the provision, also, of an improved key,conveniently usable to open either the present improved plunger-typelock or the prior plunger-type locks.

Preferred embodiments of an improved plunger-type lock, keys for saidlock, and lock and key combinations, according to this invention, aredisclosed in the accompanying drawings without, however, limiting thisinvention to the structures shown therein.

In the drawings:

FIGURE 1 is an elevational view illustrating the im- I provedplunger-type lock in locking association with an arm of a valve such asmight be used, for example, in a gas-carrying pipeline.

FIG. 2 is an elevational view as seen from the top of FIG. 1.

FIG. 3 is a side elevational view of a first form of improved keysuitable for use in 'such a lock.

FIG. 4 is a side elevational view of said key as viewed from the top ofFIG. 3; partly broken away to show some internal details.

FIG. 5 is an enlarged, central, longitudinal sectional view of saidlock.

FIG. 6 is an enlarged, central, sectional view of said key; this viewbeing taken substantially on the line 6-6 of FIG. 4.

FIG. 7 is a central, longitudinal, sectional view of said lock and saidkey, inter-associated as immediately before the manipulation of the keyto open the lock.

FIG. 8 is a view substantially the same character as FIG. 7, but showingthe lock and key as immediately following the manipulation of the key toopen the lock.

FIG. 9 is a cross-sectional view of the lock substantially on the line9-9 of FIG. 7.

FIG. 10 is a cross-sectional view of the lock and key substantially onthe line 1010 of FIG. 8.

FIG. 11 is a side elevational view of a second or modi- 3,933,015Patented May 8, 1862 2 fied form of improved key according to thisinvention, usable with the disclosed plunger-type lock.

FIG. 12 is a side elevational view of the modified key as viewed fromthe right side of FIG. 11.

FIG. 13 is an enlarged, central, longitudinal, sectional view of themodified key, substantially on the line 1313 of FIG. 11.

FIG. 14 is a cross-sectional view of the modified key, substantially onthe line 14-14 of FIG. 13.

FIG. 15 is a cross-sectional view of the modified key, substantially onthe line 15-45 of FIG. 13.

FIG. 16 is a side elevational view, at about the same scale as FIGS. 11and 12, of the modified key in the disclosed plunger lock, the latterbeing broken away to show operation of the key preliminary to unlockingof the lock.

FIG. 17 is a view generally similar to FIG. 16, but showing operation ofthe key to open the lock.

The lock, as may be understood from FIG. 5, comprises a cylindricalshank 2 having at its upper end (as viewed in the drawings) an integralenlarged head 4, and, at its lower end, a removable enlarged cup-shapedhead 6 formed with an internal annular groove 8 which functions as alocking groove when the shank 2 is seated at its inner-most position inthe head 6, as illustrated in FIGS. 5 and 7. A similar supplementalinternal annular groove 10 may optionally be employed Within the head 6to permit locking of the lock, with its heads 4 and 6 somewhat fartherapart than shown in FIGS. 5 and 7 as may sometimes be desirable ornecessary.

The shank 2 and the head 4 are formed with bores and counterbores 12, I4and 16 therein which respectively accommodate therewithin a lowerportion 18 of a slidable operating member 20, an enlarged upper portion22 of said slidable operating member and a retaining plug 24 which is sotightly fitted into the bore 16 that it may not acxidentally becomedislodged therefrom.

Toward the lower end of shank 2 are provided two locking balls 26disposed at opposite sides of the lower portion 18 of the operatingmember 20 within a trans verse bore 28 which extends completely throughthe shank and intersects the bore 12. The balls 26 fit precisely but,nevertheless, movably in the bore 28 and are held against dislodgmentfrom the latter by slight inward projections 30 of metal formed at theopposite extremities of bore 28 by peening or knicking the metal of theshank 2 at points marked 32, in a well-understood manner. When theoperating member 20 is in its lowermost position in relation to theshank 2, as shown in FIGS. 5 and 7, the lower portion 18 of theoperating member engages the two balls 26 and holds them in theiroutermost positions in the bore 28, in which positions they extend intointernal groove 8 in the head 6 whereby securely to hold the latter onthe shank 2. Obviously, a similar association of parts would serve tocause the balls 26 to cooperate with annular groove 10 for the samepurpose if the head 6 were not to be pushed completely onto the shank 2.

The enlarged upper portion 22 of the operating member 20 is exter'iorlyreduced to form on said member an annular shoulder 34 and to provide anannular space to accommodate a coil spring 36 which is compressedbetween the shoulder 34 and the inner end of retaining plug 24.

The end of lower portion 18 of the operating member 20 is reduced, as at38, and when the operating member 20 is slid upwardly as indicated inFIG. 8, the reduced end 38 is in transverse alignment with the balls 26,thereby permitting the latter each to move inwardly and to becomedisengaged from the groove 8 (or groove 10) and thereby enable the head6 to be completely separated from the remainder of the lock as shown inFIG. 8. It will be seen that the compressed spring 36 normally holds theoperating member 20 in locking relationship to the balls 26 and that theopening of the lock depends upon the provision of means for sliding theoperating member 20 upwardly in the shank 2 against the force of thespring 36. The latter means are in the form of the illustrated keywhich, with its operation, will now be described.

The retaining plug 24 is formed with a bore 40 extending throughout itslength, and the upper end of the upper portion 22 of the operatingmember 20 is formed with a longitudinal bore 42, these bores beingprovided in the lock to permit the insertion and operation of keyfingers as hereinafter described.

Fundamentally, the key of FIGS. 3, 4 and 6-8 includes a pair of fingerswhich enter the bore 42 and are then spread apart to enter into tightfrictional engagement with the wall of said bore, and, when held thusspread, axial or longitudinal movement of said fingers causes theoperating member 20 to slide between its locking position, as in FIGS.and 7, and its unlocked position, as in FIG. 8. More particularly, suchkey fingers, shown at 44 and 46, are formed respectively with enlargedinner ends 48 and 50 which are slidable within bores 54, 52 formedwithin a cylindrical housing 56. The mentioned fingers, as may best beseen from FIG. 10, are complementally semi-circular in cross-sectionalshape and extend through a circular aperture 58 formed in the bottom ofthe housing 56.

The lower end of finger 44, at the side thereof which intimately facesfinger 46, is tapered away from the latter finger to form a wedgeportion 60, and the lower end of finger 46, at its side which intimatelyfaces finger 44, is enlarged and tapered toward the latter finger toform a wedge portion 62 which cooperates with wedge portion 60 to spreadthe lower ends of the two fingers apart when said fingers are movedlongitudinally in relation to each other.

The lower portion of finger 46 and the enlarged upper end 50 adjoin at ashoulder 64 which normally seats with in the housing 56 at the bottom ofthe bore 52, and the length of the enlarged upper end 50 is somewhatless than the length of the bore 52. Opposed, lateral, operating arms66, disposed exteriorly of the housing 56, are formed with reduced innerends 68, as clearly shown in FIG. 4, which extend slidably through andwithin similar longitudinal slots 70, formed in opposite sides of thehousing 56; and the inner ends 68 are rigidly fixed to the enlargedupper end 50 of the finger 46.

The finger 44 extends upwardly, slidably, through aperture 58 and alongitudinal bore 71 formed in the enlarged upper end 50 of the finger46. The lower portion of finger 44 extends upwardly beyond the enlargedupper end 50 of the finger 46 to a point at which it, at a shoulder 72,adjoins the enlarged upper end 48. The enlarged upper end 48 normallyseats down upon a shoulder within the housing 56, which shoulder definesthe juncture of bore 52 with bore 54. The enlarged upper end 48 of thefinger 44 is substantially shorter than the bore 54 so that part offinger 44 and the latters upper end portion 48 are slidablelongitudinally within the housing 56.

The finger 6 is normally held yieldably in its lowermost position in thehousing 56 by coil spring 74 which is compressed between the enlargedupper end 50 of the finger 46 and the shoulder 72. The finger 44 isnormally held yieldably in its lowermost position, as shown in FIG. 6,by a coil spring 76 which is compressed between a plug 78 fixed in theupper end of the housing 56 and a bottom surface 80 of a bore 82 formed,to accommodate the latter spring, in the upper part of the enlargedupper end 48 of the finger 44. As a convenience for carrying the key,the latter may be provided with a ring 84 pivotal- 1y connected to theupper end of the housing 56.

In utilizing the described lock and key, the opening of the lock, fromits closed or locked condition shown in FIG. 5, is accomplished byinserting the fingers 44, 46 of the key into and through the bore 46 andinto the bore 42. of the lock until the lower end of the keys housing 56abuts the upper end of the head 4 of the lock, as illustrated in FIG. 7,in which association the wedge portions 60 and 62 of the keys fingersare within the bore 42. Then, while the housing 56 is thus held againstthe lock by the palm of the user hand, the operating arms 66 are pulledupwardly (i.e., rightwardly as viewed in FIGS. 3 and 4) by the user'sfingers, as far as they can go. Finger 46 and, to a lesser extent,finger 44 move with the arms 66, and such operation serves to release oropen the look.

This upward movement of the arms 66, while occurring as a continuous oruninterrupted operation, nevertheless, performs two distinct functions.The first of these functions is a wedging action which takes placebetween the wedge portions 60 and 62 to urge said portions apart. Thatwedging action occurs because initial upward movement of the arms 66 andfinger 46 takes place without any accompanying movement on the part offinger 44; this because spring '76 is stronger than the spring 74. Thisinitial movement of finger 46 continues to the extent necessary to causethe wedge portions 60 and 62 to wedge the fingers 44 and 46 apart andtightly against the wall defining the bore 42 in the locks operatingmember 20.

When the mentioned wedging action has been completed and, because ofthat action and also because of the considerably compressed condition ofspring 74, the continued upward movement of the arms 66 relative to thehousing 56 causes the two fingers 44 and 46 to move upwardly in unison,and because of the tight frictional engagement of those fingers with thelocks operating member 20 within the latters bore 42, said operatingmember is pulled upwardly within the shank 2 against the force of thespring 36, This upward movement of the locks operating member 20 withinthe shank 2 causes the lower end portion 38 of said operating member tocome into transverse register with the balls 26, as in FIG. 8, freeingsaid balls to shift inwardly to become disengaged from inner annulargroove 8 (or groove 10) of the locks head 6, thereby permitting openingof the lock by separation of the head 6 from the rest of the lock. Bythe time that the locks operating member 20 has reached its upper orunlocking position, as indicated in FIG. 8, the load or forceaccumulated in the springs 36, 74 and 76 will sufiiciently opposefurther upward movement of the fingers 44 and 46 to terminate suchupward movement of the operating member 20.

After the lock has been opened in the manner described, the userreleases arms 66, whereupon springs 74 and 76 expand and restore thefingers 44, 46 to their nonwedging or inoperative relative positionsshown in FIG. 6. As said fingers no longer grip the operating member 20of the lock, said operating member is restored by spring 36 to itsball-holding or locking position shown in FIGS. 5 and 7; and the key maybe freely withdrawn from the lock.

To put the head 6 back upon the shank 2 of the lock and to lock saidhead thereon, the keys fingers 44, 46 are reinserted in the lock and thekey is then operated by pulling its arms 66 upwardly, in the manneralready described, thereby raising the locks operating member 20 andenabling the balls 26 to move inwardly in the lock to permit theassociation of the head 6 therewith. Then, release of the arms 66permits the locks operating member 20 to descend, in the manner justdescribed, and force the balls 26 outwardly and partially into groove 8(or 10) to secure the head 6 upon the remainder of the lock against anypossible disassociation therefrom without the use of a key.

The second or modified form of key, illustrated in FIGS. 11-17, differsfrom the described first form of key chiefly in having a manuallyoperable cam member which performs the functions of the operating arms66 of the first form of key, and in having a more compact arrangement oflock-operating fingers and telescoping springs related to said fingers,

Referring particularly to FIG. 13, the second form of key hascross-sectionally semi-circular fingers 44a and 46a, the latter having awedge portion 62a at its lower end causing said fingers to be wedgedapart when finger 46a is shifted upwardly relative to finger 44a, sothat the just-mentioned fingers operate like and for the same purposesas fingers 44 and 46 of the first key.

The fingers 44a and 46a extend upwardly, slidably through an aperture,104 in the lower, flat end 106 of a cylindrical housing 56a, threadedon the upper end of which is a cap 108. An almost completely circular,integral, enlarged upper end portion 110 of finger 44a is slidablewithin the housing 56a, and a spring 112, compressed between the cap 108and portion 110, normally holds finger 44a in its lowermost positionshown in FIG. 13.

Finger 46a extends slidably upwardly through aperture 104 and alsothrough a slot 114 in portion 110, and has an enlarged plunger-likeupper end portion 116 which is eccentric with respect to finger 46a butis concentric to the housing 56a. The lower end of portion 116 seatswithin a recess 118 in the top of portion 110. The upper end of portion116 is formed as an integral extension 120 of rectangular shape incross-section, and this extension extends upwardly, slidably through arectangular aperture 122 in the cap 108 and beyond the top surface ofthe latter.

The portion 116 is slightly shouldered as at 124 to sup potr a washer126, and a coil spring 128, surrounding portion 116 and telescopedwithin spring 112, is compressed between the washer 126 and the cap 108to yieldably hold the finger 46a normally in its lowermost nonwedging ornon-operative position shown in FIG. 13.

The upper end of extension 120, protruding above the cap 108, isdisposed within a slot 130 in the cam member 100 wherein it is pivotallyheld by a suitable pivot pin or bolt 132. The cam member is shapedsubstantially as illustrated and has an operating handle 134 and first,second and third cam surfaces, numbered, respectively, 136, 138 and 140,which cooperate with the top surface of cap 108 to operate the fingers44a and 46a. Optionally, the cam member may be formed with an aperture142, permitting attachment of the key to a split key ring 144.

When cam member 100 is positioned, as in FIGS. 12 and 13, with camsurface 136 against the fiat top of cap 103, the fingers 44a and 46a arein non-wedging or nonoperative position and the keys fingers may befreely in serted into or removed from a lock of the character disclosedherein. Assuming that said fingers, in their nonwedging positions, havebeen inserted in a lock to open the latter, and that the bottom ofcylinder 56a abuts the top end of the lock as in FIG. 16, manual turningof the cam member counterclockwisely, to bring cam surface 138 intointimate contact with cap 108, as shown in said figure, causes finger46a to be raised so that the keys fingers are wedged apart to griptightly the inner surface of bore 42 of the lock. This positivelyassociates the key with the lock, but does nothing more. Optionally, theextremities of the fingers 44a and 4611 may be slightly enlarged asindicated at 44:; and 46a to localize, at said extremities, the grippingengagement of the fingers with the inner surface of the bore 42 of thelock.

Thereafter, to open the lock, the cam member 100 is given a furthercounterclockwise movement to bring cam surface 140 into intimate contactwith the cap 108, thereby raising the two inter-wedged fingers 44a and46a, concomitantly raising the locks operating member 20 from its FIG.16 position to its FIG. 17 position. This brings the reduced lower end38 of said operating member (FIG. 8) into register with the balls 26 topermit the latter to withdraw from groove 8 (or to free the locks head 6in the manner already described,

It should be observed that the disposition of the cam surfaces 136, 138and 140 is such as to yield the described operation. Additionaly,however, the springs 112 and 128 coact with portions 116 and and withthe cam member 100 to cause the latter to remain in whichever of thethree described positions to which it may be moved. Thus, while thedescribed first form of key remains associated with the upper part ofthe lock only While the arms 66 are held by the user in their raised orwedging position, the described second form of key remains securelyassociated with the upper part of the lock when either of cam surfaces138 or is in intimate contact with the cap 108. This feature,particularly where cam surface 140 is in contact with the cap 108, is agreat convenience, as the key, then, remains with the upper part of thelock in readiness for convenient, subsequent re-closing of the lock.

Re-closing of the lock, where the second form of key is employed,involves only the re-application of the head 6 to the lock and turningof the cam member 100 back to the position shown in FIGS. 12 and 13,whereafter the key readily separates from the lock.

The described operation of the keys disclosed herein is much moreconvenient than the operation of keys heretofore provided for suchlocks. Additionally, the described arrangement, under which the fingers44, 46 or 44a, 46a are wedged apart within the lock, provides a positivemeans for gripping and operating the locks operating member 20 despitethe fact that, in contrast to designs of previous locks of this type,the bore 42 of said operating member is not in any way constrictedtoward its upper end. Such constriction of the bore 42 toward its upperend, a necessary or desirable characteristic in prior plunger lock andkey arrangements, involves troublesome and costly machining to form thebore 42, while, in the presently disclosed lock, the bore 42 may beeasily and economically formed.

It should be noted, moreover, that keys, according to this invention,may be used to open prior plunger locks in which the only substantialdifference from the lock disclosed herein resides in the mentionedconstriction of the upper end of the bore 42. Obviously, the wedgedapartfingers 44, 46 or 44a, 46:: will just as efiectively grip within a borehaving a constricted upper end as they will within a bore having no suchconstriction. Because of this situation, the key disclosed herein may beused, not only with new locks, according to this invention, which may bemore economically produced, but such keys may also be used to open thementioned older type of plunger locks. Thus, by utilizing thisinvention, the advantages of the newer locks are available, while, asthe new type of key disclosed herein can open both old type and new typelocks, it is not necessary for a workman to carry both types of keys.

It will be apparent that the disclosed concepts may be utilized in otherways than disclosed herein, without, however, departing from theinvention as set forth in the accompanying claims.

I claim:

1. A key for opening a lock which has a slidable operating member whichis yieldably biased toward locking position and has a bore, opening inthe direction of movement of said operating member away from saidlocking position toward an unlocking position, said key comprising ahousing, plural, relatively slidable finger elements carried partlywithin said housing and having integral flexible fingers projecting fromsaid housing in intimate side-by-side relationship and adapted to entersaid bore, spreading means coacting with said fingers for spreading thelatter apart, in response to relative sliding movement of said fingerelements, into firm frictional engagement with wall portions of saidbore, yieldable means coasting with said housing and said fingerelements to urge said fingers outwardly relatively to said housing andmanually operable means projecting from said housing and coacting withsaid finger elements to relatively slide the latter and to impart aretracting, unison movement to said fingers, when the latter are thusspread, to cause movement of the loeks said operating member toward itsunlocking position.

2. A key according to claim 1, said spreading means comprising a wedgeformation at the end of one of said fingers and arranged to coact withanother of said fingers, upon relative longitudinal movement of said oneand other of the fingers, to spread said fingers apart, and saidmanually operable means being adapted to impart said relativelongitudinal movement to said fingers.

3. A key according to claim 2, said manually operable means including amanipulatable projection, connected with one of said fingers andaccessible at the exterior of the key for manipulation to move thefinger, connected to it, relatively to another of said fingers andthereby spread said fingers apart; and said projection being furthermanipulatable, after said spreading of the fingers, to move said fingersand said operating member, gripped by said fingers, toward said membersunlocking position.

4. A key according to claim 3, said projection extending laterally,relatively to said fingers, to the exterior of the key.

5. A key according to claim 3, said projection extending endwisely,relatively to said fingers, to the exterior of the key.

6. A key according to claim 5, said key including a manually operablecam pivotally connected to the outer end of said projection and coactingwith an adjacent portion of said housing to actuate said projection.

7. A key according to claim 6, said cam having different surfacescoacting with said housing to position said projection and the fingerconnected thereto in three difierent positions in which, (1) saidfingers are on spread, (2) said fingers are spread apart, and (3) saidfingers are firmly engaged. within the locks operating member and thelatter is in its unlocking position.

8. A key for opening a lock which has a cylindrical housing, an aninternal, cylindrical operating plunger which is axially slidableoppositely between locking and unlocking positions and is formed with abore, opening and facing in the direction of movement of the plungertoward its unlocking position; said key comprising a cylindricalhousing, a pair of longitudinally slidable finger elements having innerportions within said key housing and integral fingers projecting fromone end of the key housing, spring means within the key housing coactingwith said inner portions of the finger elements to urge said fingersoutwardly, wedge means-at the outer extremity of one of said fingerscoacting with the other of said fingers to spread the two fingers apartupon relative movement of the latter, and an extension connected to theinner portion of one of said finger elements and extending to theexterior of said key housing; the key hous ing being abuttable endwiselyagainst the lock housing with said fingers disposed within said bore,and said extension being manually movable to move one of said fingerelements relatively to the other of said elements to cause the wedgemeans to spread apart and grip said plunger within said bore, and theextension being further movable to move said plunger toward itsunlocking position.

9. A key according to claim 8, said extension being slidablelongitudinally of said key housing withina longitudinal slot formed inthe latter.

10. A key according to claim 8, said extension being slidablelongitudinally of said key housing within an aperture formed in an endof said key housing and having an external cam pivoted thereto, manuallymovable to three different positions in which difierent cam surfaces ofsaid cam coact with the key housing (1) to hold said in non-spreadrelative positions, (2) to hold said fingers in spread relativepositions, and (3) to hold said fingers in retracted positions with theplunger of the lock gripped by said fingers in unlocking position.

11. A key according to claim 1, said yieldable means comprising two coilsprings of which one is compressed between a wall of said housing andone of said finger elements and the other is compressed between saidwall and the other of said finger elements.

12. A key according to claim 1, said yieldable means comprising two coilsprings of which one is compressed between a wall of said housing andone of said finger elements and the other is compressed between saidfinger elements.

References Cited in the file of this patent UNITED STATES PATENTS878,457 Deller Feb. 4, 1908 1,470,421 Astley Oct. 9, 1923 1,923,025Morse et a1. Aug. 15, 1933 2,092,572 Deane Sept. 7, 1937 FOREIGN PATENTS104,725 Great Britain Mar. 13, 1917 449,281 Italy June 8, 1949 UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,033,016 May8, 1962 Sigurd M. Moberg It is hereby certified that error appears inthe above numbered patent requiring correction and that the said LettersPatent should read as corrected below.

Column 7, line 38, for "an an" read and an column 8, line 22, after"said", second occurrence insert fingers Signed and sealed this 28th dayof August 1962.

(SEAL) Attest:

ESTON G. JOHNSON ID L LADD Atteeting Officer Commissioner of Patents

